Union forces under the command of Union General Henry W. Wessells’ garrison of about 3,000 troops held Plymouth after its federal occupation in December 1862. The 85th Redoubt, also known as Fort Wessells, was an earthen fort built by the 85th New York Regiment to maintain Union control of the region as part of a larger set of earthworks that ringed the town. Armed with one 32 pound and one 6 pound cannon, the fort was strategically placed and stood southwest of the main works.

On April 17, 1864, an advanced Union patrol on the Washington Road was captured by Confederate cavalry and, following this first encounter, a large force of Confederate infantry soon appeared on the road. At the same time Fort Gray, two miles above Plymouth on the river bank, was also attacked by advance Confederate infantry. During the evening, skirmishing continued from the Washington Road to the Acre Road. Union General Wessells’ garrison was under attack by General Robert F. Hoke’s division of over 5,000 men.

At 6:30 P.M. on the 18th Confederates advanced their line and began an infantry assault upon the Union position; but the attack was abandoned at 8 P.M. The 85th Redoubt was then attacked and it fell to Confederate forces during one of the heaviest assaults of the Battle of Plymouth at 11 P.M. on April 18, 1864.

After heavy fighting on both land and on the Roanoke on the 19th, the final attack by Confederates during the Battle of Plymouth came early in the morning of April 20, 1864. General Hoke attacked Union works from the left and Ransom mounted an attack from the right which overwhelmed the Federal forces. Fort Williams succumbed to the assault and was the last of the major forts in the town to fall as the Federal forces surrendered to the Confederates by 10 A.M.